That is still an adventure pack though. Expansions have more than a handfull of zones, or have a handful of zones the size OF Belsavis.
Adding a planet and new level expands the things you can do in a game in multiple ways.
Something that expands on a product, in any line of business, is called an expansion of the product.
The dictionary is against you my friend ;-)
Really, all this discussion about wether or not it is worth the name of an expansion is pointless at this time. So please let's just stop doing it. Rise of the Hutt Cartel will expand the story of the game, will expand the amount of levels you can gain, will expand your total amount of skill points, will expand the abilities your character has available for themselves. It is an expansion of all these things. Let's stop battling about semantics and just measure the product on it's actual worth as soon as it is released.
I bought RotHC as soon as it was available. Do I think the product itself was worth 10 dollars? I don't know.. what I do know is that, for me, the ability to play it earlier than others was worth 10 dollars. Hence me buying it now. That is the decision I made. If it's not worth 10 dollars to you now, don't spend it now. If it is still not worth 10 dollars to you when it's released, don't spend it then. it is really that simple.
This thread helps about as much as going to the toilet does: It releaves me of some crap, but I know that soon I'll need to be releaved of it again anyway.